BACTE CELL STRUCTURE Flashcards
Are variant prokaryotic strains
characterized by biochemical
or physiological differences
BIOVARS
o Is the proper word for the
name of the species.
EPITHET
Are variant prokaryotic stain
which differ morphologically
MORPHOVARS
Are stains with distinctive
antigenic properties.
SEROVARS
Is a population of organism
that is differentiated from
populations within a particular
taxonomic category.
STRAIN
Relate to an organism’s genetic makeup,
including the nature of the genes and
constituent nucleic acids.
Genotypic Characteristics
An asexual reproduction process in
which there is a separation of the
body into two new bodies.
BINARY FISSION
- Lack peptidoglycan
- Extremophiles (halophiles,
thermophiles, anaerobic
methanogens). - Not encountered in clinical
microbiology.
ARCHAEBACTERIA
Includes Pathogenic bacteria.
* Has tropism to eukaryotic cells.
EUBACTERIA
has this
gram-negative cell wall,
includes photosynthetic,
anaerobic photosynthetic
bacteria and cyanobacteria
o Proteobacteria
– has thick grampositive wall, includes rods,
cocci, actinomycetes and
mycoplasma (wall-less
bacteria).
o Firmicutes
Small, dormant, asexual spores that
develop inside the cell as a means of
survival (not of reproduction).
ENDOSPORE
ENDOSPORE Contains ___________________ found
within the core and maintains the
spore’s dormant stage (makes up 10-
20% of the spore’s dry weight)
calcium dipicolinate,
bacteria that produce ENDOSPORES
Produced by Bacillus and Clostridium spp
- Most common used stain for
endospore. - Uses malachite green as primary
stain, safranin red as counterstain
Schaeffer-Fulton or Wirtz and
Conklin:
An extrachromosomal, closed,
circular, double-stranded element of
DNA that is associated with virulence.
Plasmids
Serves as a site for the genes to
encode for antibiotic resistance,
metabolic process, and plasmid
replication and transfer between
cells
Plasmids
Outermost structure of the bacterial
cell.
CELL ENVELOPE
bacteria with outer membrane only
Gram Neg Bacteria
Deepest layer of the cell envelope.
* Consists of a phospholipid bilayer
that surrounds the cytoplasm, and the
layer is embedded with lipoproteins
(no sterols contain).
Plasma Membrane
Referred to as the peptidoglycan or
murein layer
* A rigid structure that maintains the
shape of the cell
Cell Wall
alternating
n-acetylglucosamine (NAG) and
N-acetylmuramic acid connected
by Beta 1→4 linkages
A glycan backbone
- Composed of
Thick murein
layer - Has teichoic
acid (anchored
to the
peptidoglycan)
and
lipoteichoic
acid (anchored
to the plasma
membrane)
Gram-Positive Cell
Wall
Composed of
thin murein
layer
- Composed of
outer
membrane
(contains of
proteins,
phospholipids
and
lipopolysaccha
ride (LPS)
- LPS has three
regions
Gram-Negative
Cell Wall
Located between the outer
membrane and inner
membrane.
o Encompasses the thin
peptidoglycan layer.
o Has a gel-like matrix
containing nutrient-binding
proteins and degradative and
detoxifying enzymes.
Periplasmic Space
Are generally Gram-Positive cell
wall
* more than 60% of cell wall is lipid.
Acid-Fast Cell Wall
A waxy layer of glycolipids
and fatty acids bound to the
exterior of the cell wall.
mycolic acid
- Network of polysaccharide that
project from the cellular surfaces of
bacteria. - Found external to the cell wall of the
organism. - Covers surfaces like a film and allows
the bacteria to adhere to various
structure (skin, heart valves, prosthetic
joints and catheters).
Glycocalyx
GLYCOCALYX production can be the first step in
the formation of ________________
biofilm.
High-molecular weight
polysaccharides, except in B.
anthracis (D-glutamic acid, a
polypeptide).
* Anti-phagocytic
Capsules
Motility Characteristics
Tumbling
Listeria
monocytogenes
Motility Characteristics
Darting
Campylobacter
Motility Characteristics Rapid
darting/Shooting star
Vibrio
Motility Characteristics
Twitching
Kingella
Motility Characteristics
Gliding
Capnocytophaga
Inverted Christmas
tree/Umbrella
pattern colony
Listeria
monocytogenes
Test tube brush
pattern colony
Erysipelothrix
rhusiopathia
– may serve as
adhesins for attachment to
host cells (for establishment of
infection)
Fimbriae
contains structural
protein subunits (pilins) and
proteins located at the tips
(adhesins)
Pili
no flagellum
Atrichous
flagellum on one
pole
Monotrichous
single flagellum on
each pole
Amphitrichous
tuft of flagella at one
or both poles
Lophotrichous
Flagella all over the
organism
Peritrichous
not a true
flagella/no flagellin; a flagella-like
inside the periplasmic stage
Periplasmic flagella (aka Axial
filaments/endoflagella)
bacteria motility best seen at _________
25 deg C
